The present invention relates to transport apparatus, and more particularly to a transport apparatus which is useful, for example, in motor vehicle manufacturing plants for transporting trucks with a vehicle body placed thereon along a specified path and which is adapted to stop the truck at a desired position during transport.
As disclosed, for example, in Unexamined Japanese Utility Model Publication No. 89083/1985, apparatus of the type mentioned are already known which comprise two rails arranged side by side for supporting respective right and left metal wheels of a truck thereon, at least one of the two rails being a truck transport movable rail movable longitudinally thereof. The movable rail is made of a metal material in its entirety.
Since the wheel and the rail of the conventional apparatus are both made of metal, they are in line contact with each other when considered to be substantially undeformable elastically. Accordingly, the rolling friction between the wheel and the rail is extremely small, permitting the wheel to roll on the rail relatively easily. Even if it is attempted to transport the truck along with the rail by moving the rail, there is a strong tendency for the truck to remain unmoved owing to the inertial force of the truck, with the result that only the rail moves, failing to transport the truck reliably.
Another apparatus is known which has a movable rail the tread of which is formed with a wheel engaging recessed portion as disclosed, for example, in Unexamined Japanese Utility Model Publication No. 37910/1982.
When the rail of this apparatus is moved with a truck held at a halt, the engaging recessed portion of the moving rail gives a shock or produces noise every time the wheel is engaged in or released from the recessed portion, so that the rail is not movable smoothly.